Induction motor for a work machine

Abstract

A work machine may include a drive mechanically associated with a plurality of ground engaging elements. A 4-phase/4-sub-phase motor may be operatively associated with the drive and may include a stator, a rotor, and a 3-to-4 phase inverter. The stator may include a plurality of stator coils. The rotor may be operatively associated with the drive and may include a plurality of permanent magnets. The 3-to-4 phase inverter may be configured to provide alternating 4-phase and 4-sub-phase signals to the plurality of stator coils to produce magnetic flux with the plurality of permanent magnets to rotate the rotor.

What is claimed is: 
     
         1 . A work machine, the work machine comprising:
 a plurality of ground engaging elements;   a drive mechanically associated with the plurality of ground engaging elements; and   a 4-phase/4-sub-phase motor operatively associated with the drive, the 4-phase/4-sub-phase motor including a stator, a rotor, and a 3-to-4 phase inverter, the stator including a plurality of stator coils, the rotor operatively associated with the drive and including a plurality of permanent magnets, the 3-to-4 phase inverter configured to provide alternating 4-phase and 4-sub-phase signals to the plurality of stator coils producing magnetic flux with the plurality of permanent magnets to rotate the rotor.   
     
     
         2 . The work machine of  claim 1 , further including an engine mechanically associated with a generator, the generator in electrical communication with a control system, the control system in electrical communication with the 3-to-4 phase inverter. 
     
     
         3 . The work machine of  claim 2 , wherein the control system includes a power inverter in electrical communication with the generator and the 3-to-4 phase inverter, the power inverter configured to convert direct current received from the generator to 3-phase alternating current to supply the 3-to-4 phase inverter, the 3-to-4 phase inverter configured to convert the 3-phase alternating current to 4-phase/4-sub-phase alternating current signals. 
     
     
         4 . The work machine of  claim 2 , wherein the control system includes a rectifier and a power inverter in electrical communication with the 3-to-4 phase inverter, the rectifier in electrical communication with the generator and the power inverter, the rectifier configured to convert alternating current received from the generator to direct current to supply the power inverter, the power inverter configured to convert the direct current received from the rectifier to 3-phase alternating current to supply the 3-to-4 phase inverter, the 3-to-4 phase inverter configured to convert the 3-phase alternating current to 4-phase/4-sub-phase alternating current signals. 
     
     
         5 . The work machine of  claim 1 , wherein the plurality of stator coils includes thirty-six stator coils. 
     
     
         6 . The work machine of  claim 1 , wherein the plurality of permanent magnets includes forty-eight permanent magnets. 
     
     
         7 . The work machine of  claim 1 , wherein the plurality of stator coils are grouped into first through eighth grouped stator coils. 
     
     
         8 . The work machine of  claim 7 , wherein the first grouped stator coils is associated with a phase A, the second grouped stator coils is associated with a sub-phase A, the third grouped stator coils is associated with a phase B, the fourth grouped stator coils is associated with a sub-phase B, the fifth grouped stator coils is associated with a phase C, the sixth grouped stator coils is associated with a sub-phase C, the seventh grouped stator coils is associated with a phase D, and the eighth grouped stator coils is associated with a sub-phase D. 
     
     
         9 . The work machine of  claim 8 , wherein the phase A excitation signal is at 0°, the sub-phase A excitation signal is at 45°, the phase B excitation signal is at 90°, the sub-phase B excitation signal is at 135°, the phase C excitation signal is at 180°, the sub-phase excitation signal is at 225°, the phase D excitation signal is at 270°, and the sub-phase D excitation signal is at 315°. 
     
     
         10 . A 4-phase/4-sub-phase motor for a work machine, the 4-phase/4-sub-phase motor comprising:
 a stator;   a rotor encircled by and in operative association with the stator;   a plurality of stator coils disposed on the stator, each stator coil radially arranged and evenly spaced apart from each other;   a plurality of permanent magnets disposed on the rotor, each permanent magnet radially arranged and evenly spaced apart from each other; and   a 3-to-4 phase inverter in electrical communication with the plurality of stator coils and configured to provide alternating 4-phase and 4-sub-phase signals to the plurality of stator coils producing magnetic flux with the plurality of permanent magnets to rotate the rotor.   
     
     
         11 . The 4-phase/4-sub-phase motor of  claim 10 , wherein the plurality of stator coils are grouped into first through eighth grouped stator coils. 
     
     
         12 . The 4-phase/4-sub-phase motor of  claim 11 , wherein the first grouped stator coils is associated with a phase A, the second grouped stator coils is associated with a sub-phase A, the third grouped stator coils is associated with a phase B, the fourth grouped stator coils is associated with a sub-phase B, the fifth grouped stator coils is associated with a phase C, the sixth grouped stator coils is associated with a sub-phase C, the seventh grouped stator coils is associated with a phase D, and the eighth grouped stator coils is associated with a sub-phase D. 
     
     
         13 . The 4-phase/4-sub-phase motor of  claim 12 , wherein the phase A excitation signal is at 0°, the sub-phase A excitation signal is at 45°, the phase B excitation signal is at 90°, the sub-phase B excitation signal is at 135°, the phase C excitation signal is at 180°, the sub-phase excitation signal is at 225°, the phase D excitation signal is at 270°, and the sub-phase D excitation signal is at 315°. 
     
     
         14 . The 4-phase/4-sub-phase motor of  claim 10 , wherein the plurality of stator coils includes thirty-six stator coils. 
     
     
         15 . The 4-phase/4-sub-phase motor of  claim 10 , wherein the plurality of permanent magnets includes forty-eight permanent magnets. 
     
     
         16 . A method for achieving a desired torque density in a work machine, the method comprising:
 providing a 4-phase/4-sub-phase motor to drive a plurality of ground engaging elements of the work machine; and   configuring a 3-to-4 phase inverter of the 4-phase/4-sub-phase motor to provide alternating 4-phase and 4-sub-phase signals to a plurality of stator coils of the 4-phase/4-sub-phase motor producing magnetic flux with a plurality of permanent magnets of the 4-phase/4-sub-phase motor to rotate a rotor of the 4-phase/4-sub-phase motor.   
     
     
         17 . The method of  claim 16 , further including grouping the plurality of stator coils into first through eighth grouped stator coils. 
     
     
         18 . The method of  claim 17 , further including configuring the 3-to-4 phase inverter to supply a phase A excitation signal to the first grouped stator coils, a sub-phase A excitation signal to the second grouped stator coils, a phase B excitation signal to the third grouped stator coils, a sub-phase B excitation signal to the fourth grouped stator coils, a phase C excitation signal to the fifth grouped stator coils, a sub-phase C excitation signal to the sixth grouped stator coils, a phase D excitation signal to the seventh grouped stator coils, and a sub-phase D excitation signal to the eighth grouped stator coils. 
     
     
         19 . The method of  claim 16 , further including providing the plurality of stator coils with thirty-six stator coils. 
     
     
         20 . The method of  claim 19 , further including providing the plurality of permanent magnets with forty-eight permanent magnets.